Applied Technology in Evoked Auditory Response In Vivo Animal Cochlea by 980nm Pulsed Laser Light

Optical cochlear implant is an emerging applied technology of stimulating auditory neurons by using pulsed laser light as a stimulus to evoke neural activity instead of electrical currents. Laser stimulation has more potential in accuracy and high frequency resolution than electrical stimulation. In this paper we demonstrated a fiber laser system (980nm) to irradiate on guinea pig cochlear in vivo for the first time. The pulsed laser stimulation successfully evoked auditory nervous impulse, similar to acoustic stimulation. And the performance under different laser pulse intensity and pulse width is further tested and discussed. The results show that the 980nm pulsed laser stimulation with microsecond level width is effective and safe to evoke auditory response. Photoacoustic or photothermal effects maybe the main mechanism. In the end, we put forward some prospects of the applied technology in cochlear implant.

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Transient absorption changes in vivo during photodynamic therapy with pulsed-laser light

British Journal of Cancer ◽

10.1038/sj.bjc.6690361 ◽

1999 ◽

Vol 80 (3-4) ◽

pp. 344-351 ◽

Cited By ~ 19

Author(s):

B W Pogue ◽

T Momma ◽

H C Wu ◽

T Hasan

Keyword(s):

Photodynamic Therapy ◽

Transient Absorption ◽

Laser Light ◽

Pulsed Laser

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Abstract 322: In Vivo Vibrational Photoacoustic Tomography of Perivascular Fat in Apolipoprotein E-Deficient Mice

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.36.suppl_1.322 ◽

2016 ◽

Vol 36 (suppl_1) ◽

Author(s):

Gurneet S Sangha ◽

Evan H Phillips ◽

Craig J Goergen

Keyword(s):

Apolipoprotein E ◽

Lipid Accumulation ◽

Acoustic Waves ◽

Laser Light ◽

Imaging Modality ◽

Pulsed Laser ◽

Photoacoustic Tomography ◽

Infrarenal Aorta ◽

Perivascular Fat

Vibrational Photoacoustic Tomography (VPAT) is an emerging imaging modality that utilizes pulsed laser light to induce acoustic waves and obtain tissue specific compositional information. When used in combination with ultrasound, VPAT has the potential to identify the location, size, and distribution of lipids in vivo . In our study, we hypothesized that VPAT can be used to distinguish perivascular aortic fat accumulation between apolipoprotein E-deficient (apoE -/- ) and wild-type (WT) mice. A 40 MHz central frequency transducer (Vevo2100, VisualSonics) and a ND:YAG pulsed laser (NT352C, Ekspla) were used to simultaneously obtain both long axis in vivo B-mode and VPAT images of the infrarenal aorta in three apoE -/- (8.7±0 months old) and WT controls (2.9±0 months old) mice. Pulsed laser light was specifically tuned to 1100nm and 1210nm to image blood and lipid, respectively. We then measure perivascular lipid thickness in three distinct locations along the anterior wall of the aorta. These measurements were then averaged to obtain a final perivascular fat thickness score for both the apoE -\- and WT groups. We observed greater 1210 nm signal in apoE -/- (0.47±0.14 mm) mice versus WT mice (0.32±0.11 mm; p<0.05), suggesting that apoE -/- mice have greater perivascular lipid accumulation than WT controls. These findings are significant as they show that VPAT can be used to image and track lipid accumulation in vivo . Future work will focus on monitoring luminal plaque progression in atherosclerotic murine models, including hypercholesterolemic mice on a high fat diet or rodent models of severe carotid stenosis. If successful, VPAT has the potential to be used in the clinic to 1) study atherosclerosis plaque development, 2) evaluate the effectiveness of prospective therapeutics, and 3) improve the diagnosis of atherosclerosis or related vascular diseases.

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Dual Pulsed Laser Stimulation to the Auditory Nerve in Vivo

Frontiers in Optics / Laser Science ◽

10.1364/fio.2018.jw4a.122 ◽

2018 ◽

Author(s):

Muqun Yang ◽

Tian Guan ◽

Yonghong He

Keyword(s):

Auditory Nerve ◽

Pulsed Laser ◽

Laser Stimulation

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Quantification of Formation and Remineralization of Artificial Enamel Lesions with a New Portable Fluorescence Device

Advances in Dental Research ◽

10.1177/08959374970110041801 ◽

1997 ◽

Vol 11 (4) ◽

pp. 502-506 ◽

Cited By ~ 60

Author(s):

S. Al-Khateeb ◽

J.M. Ten Cate ◽

B. Angmar-Månsson ◽

E. De Josselin De Jong ◽

G. Sundström ◽

...

Keyword(s):

Laser Light ◽

Laser System ◽

Laser Fluorescence ◽

New Device ◽

Portable System ◽

In Vivo Diagnosis ◽

Non Destructive ◽

Mineral Loss

Quantitative laser fluorescence has been reported as a useful method for the non-destructive in vitro and in vivo diagnosis of early enamel caries. A portable system for intraoral use has been developed with a new light source and filter system replacing the laser light to facilitate clinical application. This new device was validated with microradiographic and chemical analyses for assessment of mineral changes in enamel during lesion formation and remineralization in vitro and compared with the laser light equipment. A significant correlation was found between fluorescence changes and mineral loss: r = 0.79 (laser system) and r = 0.84 (portable lamp system). The correlation between the two fluorescence methods was r = 0.93. The portable fluorescence device seemed to be a promising new tool for reproducible and sensitive assesment of the severity of incipient enamel lesions.

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Picosecond Single-Photon and Femtosecond Two-Photon Pulsed Laser Stimulation for IC Characterization and Failure Analysis

ISTFA 2009: Conference Proceedings from the 35th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2009p0268 ◽

2009 ◽

Author(s):

V. Pouget ◽

E. Faraud ◽

K. Shao ◽

S. Jonathas ◽

D. Horain ◽

...

Keyword(s):

Femtosecond Laser ◽

Single Photon ◽

Pulsed Laser ◽

Laser Pulses ◽

Femtosecond Laser Pulses ◽

Ultrashort Laser Pulses ◽

Laser Stimulation ◽

Two Photon ◽

Resolution Improvement ◽

Ultrashort Laser

Abstract This paper presents the use of pulsed laser stimulation with picosecond and femtosecond laser pulses. We first discuss the resolution improvement that can be expected when using ultrashort laser pulses. Two case studies are then presented to illustrate the possibilities of the pulsed laser photoelectric stimulation in picosecond single-photon and femtosecond two-photon modes.

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Holographic moving picture recording and observation of ultrashort pulsed laser light propagation

The Review of Laser Engineering ◽

10.2184/lsj.36.201 ◽

2008 ◽

Vol 36 (Supplement) ◽

pp. 201-202

Author(s):

Yasuhiro Awatsuji ◽

Kenzo Nishio ◽

Shogo Ura ◽

Toshihiro Kubota

Keyword(s):

Light Propagation ◽

Laser Light ◽

Pulsed Laser ◽

Ultrashort Pulsed Laser

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The role of cochlear implant positioning on MR imaging quality: a preclinical in vivo study with a novel implant magnet system

European Archives of Oto-Rhino-Laryngology ◽

10.1007/s00405-021-07005-y ◽

2021 ◽

Author(s):

Pietro Canzi ◽

Marianna Magnetto ◽

Anna Simoncelli ◽

Marco Manfrin ◽

Federico Aprile ◽

...

Keyword(s):

Mr Imaging ◽

Cochlear Implant ◽

Occipital Lobe ◽

Brain Structures ◽

Magnet System ◽

High Positive Correlation ◽

Imaging Quality ◽

Signal Void ◽

Mri Surveillance

Abstract Purposes To investigate the effects for Ultra 3D cochlear implant (CI) positioning on MR imaging quality, looking at a comprehensive description of intracranial structures in cases of unilateral and bilateral CI placement. Methods Four CI angular positions (90°, 120°, 135° and 160°) at 9 cm distance from the outer-ear canal were explored. The 1.5 T MRI assessment included our institutional protocol for the investigation of brain pathologies without gadolinium application. Three investigators (two experienced neuroradiologists and one experienced otoneurosurgeon) independently evaluated the MR findings. A 4-point scale was adopted to describe 14 intracranial structures and to determine which CI positioning allowed the best image quality score and how bilateral CI placement modified MRI scan visibility. Results A high positive correlation was found between the three blinded observers. Structures situated contralateral from the CI showed high-quality values in all four placements. Structures situated ipsilaterally provided results suitable for diagnostic purposes for at least one position. At 90°, artifacts mainly involved brain structures located cranially and anteriorly (e.g., temporal lobe); on the contrary, at 160°, artifacts mostly influenced the posterior fossa structures (e.g., occipital lobe). For the bilateral CI condition, MR imaging examination revealed additional artifacts involving all structures located close to either CI, where there was a signal void/distortion area. Conclusions Suitable unilateral CI positioning can allow the visualization of intracranial structures with sufficient visibility for diagnostic purposes. Bilateral CI positioning significantly deteriorates the anatomical visibility. CI positioning might play a crucial role for patients who need post-operative MRI surveillance.

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In Vivo Assessment of Synthetic and Biological-Derived Calcium Phosphate-Based Coatings Fabricated by Pulsed Laser Deposition: A Review

Coatings ◽

10.3390/coatings11010099 ◽

2021 ◽

Vol 11 (1) ◽

pp. 99

Author(s):

Liviu Duta

Keyword(s):

Calcium Phosphate ◽

Pulsed Laser Deposition ◽

Physical Vapor Deposition ◽

Pulsed Laser ◽

Laser Deposition ◽

Current Status ◽

Micro Computed Tomography ◽

Electron Microscopies ◽

In Vivo Assessment

The aim of this review is to present the state-of-the art achievements reported in the last two decades in the field of pulsed laser deposition (PLD) of biocompatible calcium phosphate (CaP)-based coatings for medical implants, with an emphasis on their in vivo biological performances. There are studies in the dedicated literature on the in vivo testing of CaP-based coatings (especially hydroxyapatite, HA) synthesized by many physical vapor deposition methods, but only a few of them addressed the PLD technique. Therefore, a brief description of the PLD technique, along with some information on the currently used substrates for the synthesis of CaP-based structures, and a short presentation of the advantages of using various animal and human implant models will be provided. For an in-depth in vivo assessment of both synthetic and biological-derived CaP-based PLD coatings, a special attention will be dedicated to the results obtained by standardized and micro-radiographies, (micro) computed tomography and histomorphometry, tomodensitometry, histology, scanning and transmission electron microscopies, and mechanical testing. One main specific result of the in vivo analyzed studies is related to the demonstrated superior osseointegration characteristics of the metallic (generally Ti) implants functionalized with CaP-based coatings when compared to simple (control) Ti ones, which are considered as the “gold standard” for implantological applications. Thus, all such important in vivo outcomes were gathered, compiled and thoroughly discussed both to clearly understand the current status of this research domain, and to be able to advance perspectives of these synthetic and biological-derived CaP coatings for future clinical applications.

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Low-Fluence Laser Induced Fragmentation and Desorption of 3,4,9,10-Perylenetetracarboxylic Dianhydride (PTCDA) Thin Film

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.543.30 ◽

2013 ◽

Vol 543 ◽

pp. 30-34 ◽

Cited By ~ 2

Author(s):

Aljona Ramonova ◽

Tengiz Butkhuzi ◽

Viktorija Abaeva ◽

I.V. Tvauri ◽

Soslan Khubezhov ◽

...

Keyword(s):

Thin Film ◽

Carbon Dioxide ◽

Carbon Monoxide ◽

Kinetic Energy ◽

Atomic Oxygen ◽

Laser Light ◽

Pulsed Laser ◽

Molecular Fragmentation ◽

Irradiation Pulse ◽

Main Effect

Laser-induced fragmentation and desorption of fragments of PTCDA films vacuum-deposited on GaAs (100) substrate has been studied by time-of-flight (TOF) mass spectroscopy. The main effect caused by pulsed laser light irradiation (pulse duration: 10 ns, photon energy: 2.34 eV and laser fluence ranging from 0.5 to 7 mJ/cm2) is PTCDA molecular fragmentation and desorption of the fragments formed, whereas no desorption of intact PTCDA molecule was detected. Fragments formed are perylene core C20H8, its half C10H4, carbon dioxide, carbon monoxide and atomic oxygen. All desorbing fragments have essentially different kinetic energy. The mechanism of photoinduced molecular fragmentation and desorption is discussed.

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